Apparatus for treating liquids with gases



w. E. GREENAWALT. APPARATUS FOR TREATING LIQUIDS WITH GASES. APPLICATION FILED OCT- IBI'IB IB. RENEWED MAY 25, I920.

1 374,446. Patented Apr. 12, 19.21.

TYYENIOA @mm fibula/U WILLIE. GBAWALT, OF DENVER, COLODt).

" Application filed October 16, 1918, Serial No. 258,462. Renewed may 25,

. To all whom. z'fimay concern:

Be it known that I, WILLIAM E. GREENA- WALT, a citizen of the United States, residing in the city and county of Denver and State of Colorado, have invented certain new and useful Improvements in Apparatus for Treating Liquids with Gases, of which the 7 following is a specification.

Theinventionv has for its object the more effective application of gases tofliquids toaccomplish certain results, as, for example, the precipitation of metals from their solutions by a gas suchas. hydrogen sulfid, or in the flotation treatment of certain ores. It

is not, however intended to limit it to any ,..r.'part icular' use, although in describing the apparatus, its use in the flotation of ores will be kept more or less in mind.

. This apparatus may be regarded as a modification or improvement of that described in mycoending applications, Serial No. 58,748, filed ctober 30, 1915, and Serial No. 91,675,. filed April '17, 1916.

of the sub-division, or as to the power con sumption. In consequence, also, there is not obtainable either the highest grade concentrate, or. the highest possible extraction of the minerals from the gangue. v

In the present invention, as in my 00- pending applications referred to, extremely effective sub-division of the gas is accomplished by passing the gas through gas passages in an atomizer submerged in the liquid and revolving the atomizer at a high rotary speed. This is made practicable by the form of the atomizer,'and is, more particularly, due to the fact that there is no mechanical connection between the atomizer and the stationary source of gas supply. It is not probable that with high rotary speeds a practicable connection can be made between gas passages "of a gas atomizer in a liquid and a pipe supplying the gas from a stationary compressor of any kind. It would appear quite hopeless to maintainan APPARATUS FOR TREATING LIQUIDS WITHv GASES.

specification of Letters Patent. Patented Apr. 12, 1921.

1920. Serial No. 884,167.

a stationary air compressor of any sort and an atomlzer mounted, say, on a'hollow shaft rotating at a speed of, say, 500 R. P. M. Suchconnections have been tried in connec t10n with flotation apparatus,-but have never air tight connection between a pipe line of come into practical use, evidently on account. L

of the inherent mechanical difiiculties.

In my CO PBIIdIIIg applications referred to, the gas is preferably introduced into the' llquid from a stationary gas outlet and forced through the gas passages of the atom-, izer by-the pressure of the li uid in the tank on the gas. This method is preferred in mostv instances because it admits of easy regulation of the gas within wide limits, and

this regulation, in some types ofmachlnes,

is quite essential for obtaining both a' high grade concentrate and a high percentage of extractlon. It may not alwaysbe conve'n lent however, to supply the gas in this way,-

and in some types of machines close regulation of air is not necessary.

In the present apparatus the air, or gas, is supplied to the atomizer through a hollow shaft, and to get positive results an air impeller' is mounted on the hollow shaft to force the airthrough the hollow shaft and. through the gas passages in the atomizer.

The impeller, at one end of the shaft, acts as a blower, while the atomizer at the other end of the shaft may act as an exhauster while expelling the air into the liquid, f

The apparatus-will now be"'de'scribed by referring to the accompanying drawings, in which Figure 1 shows a cross section; Fig. 2 a detail section of the impeller for forcing air through the hollow shaft; Fig. 3, a horizontal section of the impeller; Fig. 4 a hor1- zontal section of the atomizer; Fig. 5, a vertical section of the atomizer, and Figs. 6.

and 7 horizontal sections, respectively, of' modified atomizers. 7 The section in Fig. 5,

is taken at right angles toy that in Fig. -1.

Fig. 8 is a small scale horizontal section on the'line-88 of Fig. 1. a

In-the drawings 1' is a the bearings 3, 4 is an impeller for forcing tank adapted to contain a liquid and the material to betreat-f i ed, 2 is a hollow shaft vertically mounted in;

gas into the hollow shaft when; rotating ata proper speed, 51s an atomizer, suspended within the tank and sub'merged'in the "liquid, which when revolved at aJ'h-igh rota speed, atomizes the air, or, gas, in the "liqui The shaft may the pulley 6.

peller.

smallest amount of'agitation of the liquid perforations I respectively). p 7 best atomization of the (gas, and usually the pact in the 'The speed at which'the shaft is rotated will ordinarily vary from 300 to 800 P. M. to getthe best results... y a

The impeller 4, has curved blades .10 arranged so as to catch"the air'and force itinto the hollow shaft, much fthe same asin an ordinary blower. The imp with the shaft. by the impeller throu h the hollow shaft and to the atomizer, w1ll depend somewhat on the shape of the impeller and the. atomizer, but with a proper impeller and a proper atomizer it will depend hnost entirely on the speed of rotation. The atomizmg effect, under the same conditions, is also almost entirely dependent upon the speed of rotatlon;

the higher speed giving the finer atomizationof the air in the liquid. A. little experimenting may be necessary in some 'cases'to determine the *mostdesirable speed for the best results for both the atomizer and the im- Some regulation may be had, without changing the spee valve 11, attahed to theimpeller. In many instances thevolume ofair is immaterial; in such cases the rotary speed will be regulated for the best atomizing effect of the air in the liquid.

The atomizer, shown in detail in Figs. 4

and 5, is preferably made with a-circular periphery and continuity of surface so as to admit of high rotary speeds with the and the smallest consumption of power.

The gas passages, which extend from the interior to the exterior, or from the central portiqn'o the atomizer toward its periphe'ry; communicate with the hollow shaft these 'gas passages may take the form of perforations as shown by7, Figs. 4 and 5; of ducts of uniform cross section 'as .shown by 17, Fig. 6, of ducts of variable cross sections as shown by27, Fig. 7 or ofboth combined as shown in Figs. 4 and 5", where blades 8 are used in connection with the 7. Blades 8, are arranged to assist in forcing the air, or, preferably, a mixture of air and liquid, toward the pe-' riphery, thus 'ving it a higher velocity imliquid and consequent greater atomization, with a high rotary speed. The

.blades will also act to create a suction and in creating a flow of air assist the impeller The atomizer is prefthrough the shaft. erably open to the liquid at the bottom through the extension 9: in this way some of 'the liquid will be drawn into the atomizer,

and, due to the blades 8, will be thoroughly mixed with the gas, and the mixture of gas,

and liquidexpelled together through the f gas passages 7 (or 17 and 27 Figs. 6' and 7, This will usually give the best results are obtaine in this way in the eller rotates The amount of air forced located above the atomizers.

d, by means of the 'peller to force the gas throu and an atomlzer may be used,

the. atomizer is produced an air 11ft. It is also .it is desired to ex e1 the gas without mixward flow of the liquid in greatly assisted, or entirely accomplished, by

having curved deflectors 12, which. deflect both the" gas and the liquid into. a vertical stream and this vertical stream creates a flow of li uid through the channels 14 and 15 upwar ly past-the atomizer, sothat all the liquid is thoroughly treated. The forcible in ection of the gas from the atomizer,

into the vertical stream, further assists in sub-dividing the gas, as also the baffles 16 as shown in Figs. 1 and 5, are placed above the atomizer to break up the circulatory motion of the liquid induced by the rapidly rotating atomizer and. to prevent undiue agitation of the surface of the liquid. In Fig. 5, which is supposed to be'taken at right angles to the plane of'section in Fig. 1, the

baffles .16 are shown in cross-section. They are held in place by the grooves 28, and are loosely fitted, so that they can be inserted and removed as desired. The curved deflectors 12' will ordinarily simply be piecesshown, in-

of wood or'metal, of the shape f serted longitudinally between the sides the tank. i

In the flotation treatment of ores the'froth rises to the top of the liquid and overflows into the froth launder 13. 1

A flow of gas may be obtained through the hollow shaft without the use of an imh it, with a properly designed atomizer. I he impeller, however, gives a more positive action, so that lower rotary speeds may be used, more gascaused to flow at the same rotary speed,

which does not produce any suction in the shaft to. cause aflow of gas- It will,'ordinarily, be preferable to expel the gas from the atomizer with cons: erable violence, and this can betterbe obtained by expelling the gas w1th a positive pressure behind it, than centrifugal force reducing the suction.

"The location 0 The baffles 16,

if desired,

above the liquid, is immaterial. Ordinarilyf the impeller for the gas will be at the upper end of the shaft and the atomizer at the lower end. The length of the shaft is of little consequence in the o eration of the apparatus, or, with the'pos tive gas current produced by the impeller, the resistance to the gas through the hollow shaft is easily s of.

v This is purely a matter of convenience."

In Fig. 1, two cells are shown, back to back, with modified arrangement in each.

In order to insure a more thorough mix ture of gas and liquid than that accom plished by the. blades 8 alone, it is desirable to insert baffles 18, Figs. 4 and 5, -in the interior ofthe atomizer. These baifles may be attached to a stationary pipe 19, if desired, and air may be introduced into the atomizer through the pipe 19 if desired. The gas and the liquid is thoroughly mixed before it enters the gas passages.

When gas and liquid are introduced into a common interior of a rotary atomizer, as in the present apparatus, it will be necessary to so proportion the-liquid inlet and the gas inlet that both liquid and gas will be sucked into the interior. The proportion of the liquid inlet to the gas inlet can readily be determined experimentally for any part cular speed of rotation and depth of liquid in the tank.

1. In apparatusfor treating l 1qu1ds w1 th gases, a tank adapted to contain a. llquid,

a rotatably m unted hollow shaft, means attached to the s aft above the li uid for causing a flow of gas through the ollow shaft, means submer ed in the li uid attached to the shaft and rotating with 11; for atomizing the as in the. liquid, and means for rotat;

ing t e shaft.

shaft workin rotating the s aft.

- gases, a rotary atomizer arranged with gas 2. In apparatus for treating liquids with gases, a tank adapted to contain a liquid, an impeller rotating in a gas, an atomizer rotating in the li uid, a hollow shaft communicating with t e impeller and the atomizer, and means for rotating the impeller the shaft and the atomizer with suflicient speed to cause a flow of gas through the hollow shaft and to atomize the gas in the liquid. 1

3. In apparatus for treating liquids with gases, a tank adapted to contain a liquid, a rotatably mounted hollow shaft, an atomizer having gas passages communicating with the hollow shaft suspended within the tank and submerged in the liquid, an impeller attached to the shaft above the liquid and arranged to force a gas through the hollow shaft to the atomizer in the liquid, and means for rotating the shaft.

4. In apparatus for treating liquids with gases, a tank adapted to contain a liquid, arotatably mounted hollow shaft, means attached to the shaft above the liquidfor causing a flow of'gas through the hollow, shaft working by pressure, means attached to the shaft and submerged in the liquid for causing a flow of gas through the hollow by, suction, and means for 5. In apparatus for treating liquids with means for mixing the passages from its interior to its exterior for atomizing a gas in the liquid, stationary as with a portion of the liquid before ejecting the gas through the gas passages, and means for rotating the atomizer.

.6. In apparatus for treating liquids with gases, a rotary atomizer arranged with gas passages extending from its interior to its exterior for atomlzing a gas in the liquid, means for mixing the gas with a portion of the liquid before it passes into the gas passages, means for passing the mixture of gas and liquid through the gas assages, and

means fer rotating the atomlzer about its.

vertical axis.

7. In apparatus for treating liquids with gases, a tank adapted .to contain a liquid and the material to be treated, a rotary atomizer suspended within the tank and submerged in the liquid and having gas passages ex tending from its interior central portion toward its periphery, means arranged for e ectinga mlxtureof gas and liquid through the gas passages from the interior central ,PQI'tlOIl of the atomizer toward its periphery and into the liquid in the tank, and means for rotating the atomizer about its vertical axis.

8. In apparatus for treating liquids" with gases, a tank adapted to contain a liquid and the material to be treated, a rotary atomizer suspended within the tank and submerged in the liquid and having gas passages communicating with the liquid in the tank and extending from the central portion of the atomizer toward its periphery,

means arranged forejecting a mixture of.

gas and liquid through the gas assages rom the interior central portion 0 the at-' omizer toward its periphery and into the liquid'in the tank, and .means for rotating the atomizer about its vertical axis.

9. In apparatus for treating liquids-with gases, a tank adapted to contain a liquid, a gas impregnator within the tank having a hollow interior in communication with the liquid in the tank, means for causing a flow of liquid in the tank into the interior of the impregnatorymeans for causing a flowof gas 1nto the interior of the impregnator, means in the interior of the impregnator for mixing the liquid and the gas, and means for ejecting the mixture of gas and liquid into the surrounding liquid in the tank.

10. In apparatus for treating liquids with gases, a tank" adapted to contain a. liquid,

a rotary atomizerhaving passages extending from its interior central portion toward its periphery suspended within the tank and submerged in the liquid, a liquid inlet to the interior of the atomizer communicating with the passages and with the liquid in the tank, a hollow shaft gas inlet communicating with the interior of the atomizer the rotary atomizer and eject both gasand liquid through the passages of the rotary atomizer into the surrounding liquid in the tank.

' 1L In apparatus for treating liquids with gases, a tank adapted to contain a liquid,

. a rotary atomizer having gas passages extendin from its interior toward its exterior suspen ed w1th1n the tank and submerged in the liquid, means for causing a flow of gas through a hollow shaft to the interior of the atomizer, means for causing a flow of liquid from the tank to the interior of through a constricted openthe atomizer ing, meansfor rotating the atomizer about its vertical axis, stationary means at the upper extremity of the hollow shaft for regulating the flow of gas through the hollow shaft, and means arranged for ejecting a mixture of gas and liquid through the gas passages from the interior toward the ex- 25 terior and into the liquid in the tank.

WILLIAM E. GREENAWALT. 

